It won't stay running

I have an 01 Dodge Dakota. Granted, I haven't been driving it much lately, but when I do, it's been running like a charm...

Yesterday, at WalMart, when I came back out and tried to start it...nothing.

I noticed the clock was reset so I figured bad battery. Well...maybe... I finally got it jump started (it took a long time!) and if I let off the gas, it died...

Any ideas? Electrically, it seems like the battery... Mechanically, it's like it's not getting enough gas (clogged filter???).

I don't know a lot about engines so does anyone else have a clue???

Taylor

I have had a problem with a bad battery where the only way it would run is with holding it at 1500 rpm, replaced the battery and everything was fine.